Motor graders are used primarily as a finishing tool to sculpt a surface of earth to a final arrangement. Typically, motor graders include many hand-operated controls to steer the wheels of the grader, position the blade, and articulate the front frame of the grader. The blade is adjustably mounted to the front frame to move relatively small quantities of earth from side to side. The articulation angle is adjusted by rotating the front frame of the grader relative to the rear frame of the grader.
To produce a variety of final earth arrangements, the blade and the frame may be adjusted to many different positions. On most motor graders, it is possible for an operator to adjust the blade or the frame such that the blade collides with a tire or the frame and damages the motor grader. To forestall such operator-induced damage, it is desirable to provide a method for automatically preventing contact between the blade and the frame.